Field of the Invention
The present invention relates to a driving module and a lens device using the same, and more particularly to an anti-tilt electromagnetic motor which is able to prevent the tilting of an element supported thereby and a lens device using the same.
Description of the Related Art
Generally, an electronic device includes a driving module to drive an element to move a predetermined distance. For example, an electronic device having an image-capture function usually includes a driving module to generate driving power. One or more optical lens units of the electronic device are driven by the driving power to move along an optical axis, so as to facilitate auto-focus and auto-zoom controls.
However, since the driving module includes a complex driving member, such as stepper motor, ultrasonic motor, or piezoelectric actuators, etc. to generate the driving power, and the driving power has to be transmitted by a number of transmission elements, it is not easy to assemble and the manufacturing cost is high. In addition, the conventional driving module is also large in size and has a high power consumption due to its complex construction.
U.S. Pat. No. 7,869,150 discloses a camera module including a lens assembly and a driving element. The lens assembly is slidably connected to a shaft. The driving element includes a yoke, a coil, and a magnet. The magnet is disposed on one side of the lens assembly. When an electronic current passes through the coil, the lens module is controlled to move up and down by the magnetic force generated by the coil. In addition, a friction force system is established between the lens assembly and the shaft via the magnetic force generated between the yoke and the magnet. Therefore, the lens assembly is positioned via the friction force system. However, if an outer force (due to collision or swinging) is applied to the camera module, the lens assembly may move away from the magnet, and the magnetic force is gradually decreased as the distance increases. As a result, the reliability of the camera module is degraded.
US patent application 2012/0320467 discloses an image capturing device including a lens barrel and a housing. The lens barrel is disposed on the housing via an elastic member, and thus the tilting due to collision of the lens barrel with the other elements during operation is prevented. However, the lens barrel may swing in the housing as an outer force is applied to the device. Thus, the image quality of the image capturing device is not ensured.
Therefore, a driving module having the advantages of high reliability is desired by the manufactures.